Image forming device, image forming method, printer driver program, and image forming system

ABSTRACT

The image forming device of this invention includes a control unit and a storage unit. The control unit determines whether or not data for printing which has been inputted while the power save mode is being executed is data for printing to which a control command is appended that commands the reduction of electrical power consumption. If it is data for printing to which a control command is appended, then the control unit does not execute any image forming operation, but instead stores this data for printing with control command appended in the storage unit. However, if data for printing to which no control command is appended is inputted, then the control unit changes over to the operating mode and, after having performed image forming operation for this data for printing to which no control command is appended, performs image forming operation for that data for printing with control command appended within the storage unit, which has the same identification information as the data for printing to which no control command is appended.

CROSS REFERENCE

This Nonprovisional application claims priority under 35 U.S.C. §119(a)on Patent Application No. 2008-182206 filed in Japan on Jul. 14, 2008,the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to an image forming device which performsimage forming operation on the basis of data for printing, an imageforming method which is executed by an image forming device, a printerdriver program which his installed upon an information processing devicewhich is connected to an image forming device, and an image formingsystem in which an information device and an information processingsystem are connected together.

With an image forming device which performs image forming operation by amethod of electronic photography, it is necessary to raise thetemperature of a fixing device during image forming operation to a settemperature which is greater than or equal to the melting temperature ofthe toner which is employed. However, if this set temperature ismaintained even while waiting for image forming operation, then uselessconsumption of electrical power takes place.

Thus it has been arranged for it to be possible, while waiting for imageforming operation, to execute a power save mode (a power economy mode),in which the amount of electrical power consumption is less than duringthe operating mode in which image forming operation is possible. Forexample, in Japanese Laid-Open Patent Publication 2001-209514, there isdisclosed a printing system with which it is arranged, while the imageforming device is executing the power save mode, not to output anycancellation request which commands cancellation of the power save modefrom an external device to the image forming device. This structuremakes it possible, with an image forming device to which a plurality ofexternal devices are connected, to prevent decrease of the advantageouseffect of power saving occurring due to frequent cancellation of thepower save mode.

However, if a plurality of external devices are connected to the imageforming device, then a complicated operation is required for commandingall of the external devices to limit transmission of cancellationrequests, in order to ensure that the power save mode of the imageforming device is not cancelled. Moreover, it is necessary to transmitthe data for printing from the external devices when the image formingdevice is not executing the power save mode, and there is a possibilitythat it may become necessary to transmit the same data for printing froman external device several times. Due to this, the processing by theexternal devices becomes complicated.

Thus it is contemplated, along with the data from printing, to outputfrom the external devices commands which command whether or not thepower save mode is to be maintained, and to store data for printingwhich is accompanied by a command which commands for the power save modeto be maintained internally to the image forming device. When a commandis inputted to the image forming device which commands the power savemode to be cancelled, then the power save mode is cancelled, and imageforming operation is performed for the data for printing which has beeninputted and also for the data for printing which has been stored.However, in a system in which a plurality of external devices areconnected to an image forming device, since data for printing whichappertains to a plurality of users is outputted to the single imageforming device, accordingly there is a possibility that data forprinting which appertains to some user other than the user who hascommanded cancellation of the power save mode may be stored within theimage forming device. When a command is inputted which commandscancellation of the power save mode and image forming operation for allof the data for printing which the image forming device is storing comesto be performed, then printed documents which appertain to a pluralityof users are discharged in succession. As a result, not only is therethe problem that it necessary to perform the task of separating printeddocuments which appertain to the plurality of users and of distributingthese documents to those users, but also there is the problem that itbecomes impossible to ensure the secrecy of documents which are printed,since the user who has issued a command to cancel the power save mode isable to get hold of printed documents which appertain to other users.

The object of this invention is to provide an image forming device, animage forming method, a printer driver program, and an image formingsystem, which can prevent the successive discharge of printed documentswhich appertain to a plurality of users, by only performing imageforming operation on the basis of the data for printing which appertainsto that user who has commanded cancellation of the power save mode.

SUMMARY OF THE INVENTION

The image forming device according to this invention is one whichperforms image forming operation upon recording paper on the basis ofdata for printing which has been inputted from an external device alongwith identification information related to a user, and includes acontrol unit and a storage unit. The control unit controls image formingoperation so as selectively to execute either an operating mode in whichthe state of electrical power consumption is such that image formingoperation can be executed, or a power save mode in which the state ofelectrical power consumption is lower than during image formingoperation. And the storage unit stores data for printing which has beeninputted while the power save mode is being executed, and to which acontrol command is appended which commands reduction of electrical powerconsumption, along with the identification information. Here the controlunit, when data for printing to which no control command is appended isinputted while the power save mode is being executed, changes over fromthe power save mode to the operating mode, performs image formingoperation on the basis of the data for printing to which no controlcommand is appended, and performs image forming operation on the basisof, among the data for printing which is stored in the storage unit,that data for printing with control command appended which has the sameidentification information as the data for printing to which no controlcommand is appended.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic elevation view of an image forming deviceaccording to an embodiment of the present invention;

FIG. 2 is a block diagram of an image forming system according to anembodiment of the present invention;

FIG. 3 is a flow chart showing a processing sequence executed by aninformation processing device which is included in the image formingsystem according to a first embodiment of the present invention;

FIG. 4 is a figure showing an example of a display screen which isdisplayed by this information processing device;

FIG. 5 is a flow chart showing a portion of a processing sequenceexecuted by an information processing device which is included in theimage forming system according to a first embodiment of the presentinvention;

FIG. 6 is a flow chart showing a processing sequence executed by aninformation processing device which is included in the image formingsystem according to a second embodiment of the present invention;

FIG. 7 is a figure showing an example of a display screen which isdisplayed by this information processing device; and

FIG. 8 is a flow chart showing a portion of a processing sequenceexecuted by an information processing device which is included in theimage forming system according to a third embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

The image forming device 100 shown in FIG. 1 is a multi-purpose devicewhich is endowed with both a copy function and a printer function, andcreates color images or monochrome images upon blank paper stock byperforming an electronic photography image forming operation on thebasis of data for printing. This image forming device 100 comprises acontrol unit 10, a communication unit 20, a paper supply unit 80, alaser scan unit (LSU) 90, image forming units 30A through 30D, anintermediate transcription unit 40, a secondary transcription unit 50, afixing unit 60, and a manuscript reading unit 70.

The control unit 10 controls the various units of the image formingdevice 100 as a whole. The communication unit 200 inputs data from anexternal device and/or outputs data to an external device. Duringprinter operation, data for printing is inputted to the image formingdevice 100 from an external device 100 via this communication unit 200.

The manuscript reading unit 70 is the “image reading unit” of theClaims, and comprises a manuscript support 71A, a manuscript support71B, and an automatic manuscript conveyance device 72. The automaticmanuscript conveyance device 72 is supported so as to be capable ofexposing or covering the upper surfaces of the manuscript supports 71Aand 71B, and conveys a manuscript one page at a time via the manuscriptsupport 71B. During copy operation, this manuscript reading unit 70reads data for printing from a manuscript which has been laid upon theupper surface of the manuscript support 71A, or from a manuscript whichis conveyed over the manuscript support 71B by the automatic manuscriptconveyance device 72.

The LSU 90 irradiates laser light, which has been modulated according todata for printing inputted via the communication unit 20 or according todata for printing read by the manuscript reading unit 70, towards theimage forming units 30A through 30D.

These four image forming units 30A through 30D form toner images of fourdifferent respective colors: black, and cyan, magenta, and yellow whichare the three primary colors for subtractive mixing.

The image forming unit 30A comprises a photosensitive drum 31A, anelectrification unit 32A, and a development unit 33A. Theelectrification unit 32A electrifies the circumferential surface of thephotosensitive drum 31A in a uniform manner. After this circumferentialsurface of the photosensitive drum 31A has been thus electrified by theelectrification unit 32A, it is scanned by the laser light from the LSU90, and thereby a latent electrostatic image is created upon thephotosensitive drum 31A, corresponding to the black color component ofthe data to be printed. Then black toner is supplied to thecircumferential surface of the photosensitive drum 31A of thisdevelopment unit 33A, and thereby the electrostatic latent image isbrought out as a black toner image.

The image forming units 30B through 30D have similar structures to thatof the image forming unit 30A, and respectively create cyan, magenta,and yellow toner images upon their respective photosensitive drums 31Bthrough 31D.

The intermediate transcription unit 40 comprises an endless intermediatetranscription belt 41 and transcription units 42A through 42D. The tonerimages of the various colors which have been formed upon thephotosensitive drums 31A through 31D by the respectively image formingunits 30A through 30D are transcribed onto the intermediatetranscription belt 41 by transcription electric fields which are createdby the respective transcription units 42A through 42D.

The paper supply unit 80 comprises a paper supply cassette 81 and amanual feed tray 82. Blank paper stork which is stored in the papersupply cassette 81 or in the manual feed tray 82 is supplied, one sheetat a time, to between the intermediate transcription belt 41 and thesecondary transcription unit 50. The secondary transcription unit 50transcribes the toner image upon the intermediate transcription belt 41onto this sheet of blank paper which has been supplied from the papersupply unit 80.

Using a heat application and pressurization roller, the fixing unit 60applies heat and pressure to this sheet of paper upon which the tonerimage has been transcribed, and thereby thermally fixes the toner imageupon this paper sheet. During the image forming operation, the controlunit 10 executes an operating mode in which the temperature of this heatapplication roller of the fixing unit 60 is maintained at the tonermelting temperature. And, during execution of this operating mode, inorder to maintain the temperature of this heat application roller at thetoner melting temperature, the fixing unit 60 consumes a comparativelylarge amount of electrical power. On the other hand, while waiting forthe image forming operation, the control unit 10 executes a power savemode in which the temperature of the heat application roller iscontrolled to a temperature which is lower than the toner meltingtemperature, and thereby the amount of consumed electrical power isreduced. The control unit 10 may, for example, change over from theoperating mode to the power save mode when the state of waiting forimage forming operation has continued for a predetermined time period.

In the image forming system shown in FIG. 2, as one example ofutilization, an image forming device 100 and an information processingdevice 200 are connected together via a LAN 2. The image forming device100 and the information processing device 200 may also be connectedtogether via the internet or via a public telephone circuit. Moreover, aplurality of such information processing devices 200 may also beconnected to the image forming device 100.

The control unit 10 of the image forming device 100 is the “controlunit” of the Claims, and comprises a ROM 102, a RAM 103, an image memory104, interfaces 105 through 113, and a sensor 120, all of these beingconnected to a CPU 101.

The ROM 102 stores a program which controls the operation of the CPU101. The RAM 103 is used for temporarily storing data which has beeninputted to the CPU 101 and data which is to be outputted. A memory areaMA1 within this RAM 103 is allocated to a timer which timespredetermined time periods by counting clock pulses outputted from aninternal clock not shown in the figures. And the image memory 104 is the“storage unit” of the Claims, and stores data to be printed.

The intermediate transcription unit 40, the secondary transcription unit50, the fixing unit 60, the manuscript reading unit 70, the paper supplyunit 80, the LSU 90, the actuation panel unit 130, and the communicationunit 20 are connected to the respective interfaces 105 through 113. TheCPU 101 controls the operation of the various units in an integratedmanner via the interfaces 105 through 113, according to the programwhich is stored in the ROM 102.

The sensor 120 detects when the upper surfaces of the manuscript support71A and 71B are covered over by the automatic manuscript conveyancedevice 72, and outputs a detection signal to the CPU 101. And theactuation panel unit 130 inputs actuation data for the key switches tothe CPU 101 via the interface 113.

The information processing device 200 is the “external device” of theClaims, and comprises a CPU 201, a ROM 202, a RAM 203, a HDD 204, andinterfaces 205 through 208.

The CPU 201 executes processing according to a program which is storedin advance in the ROM 202. The RAM 203 is used for temporarily storingdata which has been inputted to the CPU 201 and data which is to beoutputted. Application programs are installed upon the HDD 204, andinclude a printer driver program P1 according to the present invention.A display controller 210, a keyboard 211, a mouse 212, and acommunication unit 209 are respectively connected to the interfaces 205through 208. Via the LAN 2, the communication unit 209 performs inputand output of data to and from the communication unit 20 of the imageforming device 100.

The display controller 210 displays a display screen upon a display 213on the basis of display data which has been supplied from the CPU 201.And the actuation data for the keyboard 211 and the mouse 212 areinputted to the CPU 201 via their respective interfaces 207 and 208.

In the following, a processing sequence executed by the informationprocessing device and the image forming device which constitute theimage forming system according to the first embodiment of the presentinvention will be explained with reference to FIGS. 3 through 5. Asshown in FIG. 3, when, during creation of data for printing by anapplication program such as word processing software or the like (a stepS1), the CPU 201 of the information processing device 200 receives acommand (a step S2) for printing processing by the image forming device200, it starts the printer driver program P1 which is installed upon theHDD 204 (a step S3). And, according to this program P1, the CPU 201supplies to the display controller 210 display data for, for example,the printer driver screen G1 shown in FIG. 4 (a step S4). Due to this,the printer driver screen G1 is displayed upon the display 213.

As shown in FIG. 4, this printer driver screen G1 includes tabs for amain screen G1A, a paper stock screen GCB, a print settings screen G1C,a watermark screen G1D, and a version screen G1E.

On the main screen G1A, there are displayed a direction setting module301, an image quality setting module 302, a number of copies settingmodule 303, a paper supply setting module 304, an order selection module305, and a power save setting module 306. The direction setting module301 receives input for setting the printing direction. The productquality setting module 302 receives input for setting the quality of theprinting result. The number of copies setting module 303 receives inputfor setting the number of copies to be printed. The paper supply settingmodule 304 receives input for setting the paper supply method. The ordersetting module 305 receives input for setting the printing order. Andthe power save setting module 306 receives input for setting theelectrical power consumption state of the image forming device 200.

When a command is issued via the power save setting module 306 of thismain screen G1A for “power save printing” setting, the CPU 201 adds acontrol command to the data for printing to be outputted to the imageforming device 200 which commands the reduction of the amount ofconsumed electrical power (steps S5 and S6).

And, when an OK button on the main printer driver screen G1A is clicked,the CPU 201 outputs data for printing to the image forming device 100along with identification information (steps S7 and S8). Thisidentification information is information which specifies theinformation processing device 200, such as, for example, addressinformation of the information processing device 200 (IP address or MACnumber), or information such as the device type and name or the like.

As shown in FIG. 5, when its power supply is turned on, the CPU 101 ofthe image forming device 100 performs warming up (a step S11). Thiswarming up process includes processing to raise the temperature of theheat application roller of the fixing unit 60 up to a set temperature,which is greater than or equal to the melting temperature of the toner.

When warming up has been completed, the CPU 101 waits for input of datafor printing (a step S12). And, when data for printing is inputted,image forming operation is performed on the basis of this data forprinting (a step S20). But, if the timer T1 times the predetermined timeperiod without any data for printing being inputted (a step S13), thenthe CPU 101 changes over to the power save mode (a step S14).

And, while executing the power save mode, the CPU 101 waits for input ofdata for printing from the information processing device 200 (a stepS15).

When data for printing is inputted, after having temporarily stored thisdata for printing in the image memory 104 along with its identificationinformation (a step S16), the CPU 101 makes a decision as to whether ornot any control command is appended to this data for printing, in otherwords as to whether or not data for printing to which a control commandis appended has been inputted (a step S17).

If data for printing to which a control command is appended has beeninputted, then the CPU 101 continues to executed the power save mode.But if no limitation information is appended to the data for printing,in other words if data for printing with no control command appended hasbeen inputted, then the CPU 101 changes over from the power save mode tothe operating mode (a step S18), and performs image forming operationafter having raised the temperature of the heat application roller togreater than or equal to the melting temperature of the toner (steps S19and S20).

Then the CPU 101 makes a decision as to whether or not the data forprinting which is stored in the image memory 104 includes any data forprinting to which a control command is appended which has the sameidentification information as the identification information of the datafor printing with no command appended which has been inputted this time(a step S21). And, if any data for printing, to which a control commandis appended whose identification information is the same as theidentification information of the data for printing with no commandappended which has been inputted this time, is stored in the imagememory 104, then the CPU 101 performs image forming operation on thebasis of this data for printing (the step S20). On the other hand if nodata for printing, to which a control command is appended whoseidentification information is the same as the identification informationof the data for printing with no command appended which has beeninputted this time, is stored in the image memory 104, then the CPU 101returns to the state of waiting for input of data for printing (i.e.returns from the step S21 to the step S12).

The processing described above corresponds to the “image forming method”of the present invention; and in this processing, in the state in whichthe image forming device 100 is executing the power save mode, it isselected whether to continue the power save mode or to change over tothe operating mode, according to whether or not the data for printingwhich has been inputted from the information processing device 200 isdata for printing to which a control command is appended. Due to this,it is possible to control the electrical power consumption state of theimage forming device 100 in a simple and easy manner from theinformation processing device 200, by either adding a control command tothe data for printing, or not adding any such control command thereto.Furthermore, along with it being possible to eliminate any need forperforming the task of separating documents which appertain to aplurality of users and distributing these documents to those users, itis also possible to ensure the secrecy of documents which are printed bypreventing the user who has issued a command to cancel the power savemode from getting hold of printed documents which appertain to otherusers.

Yet further, if data for printing to which a control command is appendedis inputted from the information processing device 200 and the powersave mode, which is being executed, is continued, then, along withstoring this data for printing to which a control command is appended inthe image memory 204, when data for printing whose identificationinformation is the same but to which no command is appended is inputted,this data is presented to the image forming operation. Accordingly, itis not necessary to repeat the output of the same data for printing fromthe information processing device 200, so that it is possible to preventcomplication of the task of printing by the information processingdevice 200.

And furthermore, it is possible to perform image forming operation basedupon data for printing to which no control command is appended, which isconsidered to be of a high urgency level, before image forming operationon the basis of the data for printing to which a control command isappended.

In the following, a sequence of processing executed by an informationprocessing device which is included in an image forming system accordingto a second embodiment of the present invention will be explained withreference to FIGS. 6 and 7. In the sequence of processing shown in FIG.3, this information processing device 200 according to the secondembodiment executes steps S31 and S32, as shown in FIG. 6, between theprocessing of the step S6 and the processing of the step S7. In the stepS31, the CPU 201 receives input of a password from a password inputmodule 307 upon the main screen G2A of the printer driver screen G2shown in FIG. 7. And, in the step S32, the CPU 201 appends this passwordwhich has been inputted to the data for printing which is to beoutputted to the image forming device 100, as identification informationwhich specifies the user.

It should be understood that the printer driver screen G2 shown in FIG.7 is the same as the printer driver screen shown in FIG. 4, except forthe point that it includes the password input module 307.

By outputting information from the information processing device 200which specifies the user of the image forming device 100 along with thedata for printing, even in an environment in which a plurality of userscan utilize a single information processing device 200, it is possibleto provide image forming operation which discriminates between the datafor printing for these various users

In the following, a sequence of processing executed by an image formingdevice which is included in an image forming system according to a thirdembodiment of the present invention will be explained with reference toFIG. 8.

When, during the power save mode, data for printing to which no commandis appended is inputted to the CPU 101 of this image forming deviceaccording to this third embodiment of the present invention, the CPU 101changes over to the operating mode and performs image forming operationfor this data for printing with no command appended (a step S30). Then,among the data for printing to which a control command is appended whichis stored in the image memory 204, the CPU 101 performs image formingoperation only for that data for printing to which a control command isappended, which has the same identification information as this data forprinting with no command appended that has been inputted this time (thesteps S21 through S30).

When, in the image memory 204, there is no further data for printing towhich a control command is appended, which has the same identificationinformation as this data for printing with no command appended that hasbeen inputted this time, then the CPU 101 changes over from theoperating mode to the power save mode, and waits (the step S14) forinput of data for printing.

While the power save mode is being executed, it is possible to reducethe consumption of electrical power by immediately resuming the powersave mode after image forming operation has been performed for all ofthe data for printing which has the same identification information asthe data for printing with no appended command which has been inputted.

All of the features of the embodiments described above are cited by wayof example, and should not be considered as being limitative of thepresent invention. The scope of the present invention is defined, not byany features of the embodiments described above, but solely by the rangeof the Claims. Moreover, it is intended that all changes which preservethe same meaning and scope as the range of the Claims, are to beincluded within the range of the present invention.

1. An image forming device which performs image forming operation uponrecording paper on the basis of data for printing which has beeninputted from an external device along with identification informationrelated to a user, comprising: a control unit which controls imageforming operation so as selectively to execute either an operating modein which the state of electrical power consumption is such that imageforming operation can be executed, or a power save mode in which thestate of electrical power consumption is lower than during image formingoperation; and a storage unit which stores data for printing which hasbeen inputted while said power save mode is being executed, and to whicha control command which commands reduction of electrical powerconsumption is appended, along with said identification information;wherein said control unit, when data for printing to which no controlcommand is appended is inputted while said power save mode is beingexecuted, changes over from said power save mode to said operating mode,performs image forming operation on the basis of said data for printingto which no control command is appended, and performs image formingoperation on the basis of, among the data for printing which is storedin said storage unit, that data for printing with the control commandwhich has the same identification information as said data for printingto which no control command is appended.
 2. An image forming deviceaccording to claim 1, wherein if, during the execution of said operatingmode, a predetermined time period has elapsed without image formingoperation being performed, said control unit performs changeover fromsaid operating mode to said power save mode.
 3. An image forming deviceaccording to claim 1, wherein, among said data for printing to which nocommand is appended and said data for printing to which a controlcommand is appended having the same identification information, saidcontrol unit first executes image forming operation on the basis of saiddata for printing to which no command is appended, before performingimage forming operation on the basis of said data for printing to whicha control command is appended.
 4. An image forming device according toclaim 2, wherein, among said data for printing to which no command isappended and said data for printing to which a control command isappended having the same identification information, said control unitfirst executes image forming operation on the basis of said data forprinting to which no command is appended, before performing imageforming operation on the basis of said data for printing to which acontrol command is appended.
 5. An image forming device according toclaim 3, further comprising a plurality of paper delivery units each ofwhich stores recording paper upon which image forming has beencompleted; and wherein said control unit discharges the recording paperupon which image forming has been completed for said data for printingto which no command is appended and the recording paper upon which imageforming has been completed for said data for printing to which a controlcommand is appended having the same identification information, to thesame one of said paper delivery units.
 6. An image forming deviceaccording to claim 4, further comprising a plurality of paper deliveryunits each of which stores recording paper upon which image forming hasbeen completed; and wherein said control unit discharges the recordingpaper upon which image forming has been completed for said data forprinting to which no command is appended and the recording paper uponwhich image forming has been completed for said data for printing towhich a control command is appended having the same identificationinformation, to the same one of said paper delivery units.
 7. An imageforming device according to claim 5, wherein said control unitdischarges the recording paper upon which image forming has beencompleted for said data for printing to which no command is appended andthe recording paper upon which image forming has been completed for saiddata for printing to which a control command is appended, in differentpaper ejection directions.
 8. An image forming device according to claim6, wherein said control unit discharges the recording paper upon whichimage forming has been completed for said data for printing to which nocommand is appended and the recording paper upon which image forming hasbeen completed for said data for printing to which a control command isappended, in different paper ejection directions.
 9. An image formingdevice according to claim 1, wherein, after image forming operation onthe basis of that data for printing to which no command is appended andthat data for printing to which a control command is appended which havethe same identification information has been completed, said controlunit returns to said power save mode.
 10. An image forming deviceaccording to claim 1, wherein said identification information isinformation which specifies a user.
 11. An image forming deviceaccording to claim 1, wherein said identification information isinformation which specifies an external device which has outputted saiddata for printing.
 12. An image forming method which, during theexecution of a power save mode in which the state of electrical powerconsumption is lower than during image forming operation on the basis ofdata for printing, when data for printing has been inputted from anexternal device along with identification information related to a user:determines whether this data for printing is data for printing to whicha control command which commands reduction of electrical powerconsumption is appended, or is data for printing to which no suchcontrol command is appended; if this data for printing is data forprinting to which a control command is appended, stores said data forprinting in a storage unit along with identification information; and ifit is data for printing to which no such control command is appended,cancels the power save mode which is being executed, and, along withperforming image forming operation on the basis of said data forprinting to which no control command is appended, also performs imageforming operation on the basis of that data for printing with thecontrol command which is stored in said storage unit, and which has thesame identification information as said data for printing to which nocontrol command is appended.
 13. An image forming method according toclaim 12, wherein, after image forming operation on the basis of thatdata for printing to which no command is appended and that data forprinting to which a control command is appended which have the sameidentification information has been completed, said power save mode isreturned to.
 14. An image forming method according to claim 12, whereinif, during the execution of an operating mode in which image formingoperation can be started, a predetermined time period has elapsedwithout image forming operation being performed, changeover is performedto said power save mode.
 15. An image forming method according to claim13, wherein if, during the execution of an operating mode in which imageforming operation can be started, a predetermined time period haselapsed without image forming operation being performed, changeover isperformed to said power save mode.
 16. A printer driver program for animage forming device, which is installed upon an information processingdevice having a display unit, and which is executed during the output ofdata for printing to said image forming device, the printer driverprogram causing said information processing device to execute: displayprocessing to display a display screen upon said display unit to receiveselection input to selectively set reduction of electrical powerconsumption of said image forming device, and to receive setting inputof authentication information which specifies a user of said imageforming device; data creation processing to create, according to saidselection input, either data for printing to which a control command isappended to command reduction of electrical power consumption, or datafor printing to which no control command is appended; and outputprocessing to output said authentication information which has beeninputted and set, along with said data for printing to which a controlcommand is appended or said data for printing to which no controlcommand is appended.
 17. A printer driver program for an image formingdevice, which is installed upon an information processing device havinga display unit, and which is executed during the output of data forprinting to said image forming device, the printer driver programcausing said information processing device to execute: displayprocessing to display a display screen upon said display unit to receiveselection input to selectively set reduction of electrical powerconsumption of said image forming device; data creation processing tocreate, according to said selection input, either data for printing towhich a control command is appended to command reduction of electricalpower consumption, or data for printing to which no control command isappended; and output processing to output authentication informationwhich specifies said information processing device, along with said datafor printing to which a control command is appended or said data forprinting to which no control command is appended.
 18. An image formingsystem, in which an image forming device performing image formingoperation on recording paper according to printing data inputted withidentification information on a user, and at least one informationprocessing device having a display unit, are connected together so as tobe capable of communication, the image forming device comprising: acontrol unit which controls image forming operation so as selectively toexecute either an operating mode in which the state of electrical powerconsumption is such that image forming operation can be executed, or apower save mode in which the state of electrical power consumption islower than during image forming operation; and a storage unit whichstores data for printing which has been inputted while said power savemode is being executed, and to which a control command which commandsreduction of electrical power consumption is appended, along with saididentification information; wherein said control unit, when data forprinting to which no control command is appended is inputted while saidpower save mode is being executed, changes over from said power savemode to said operating mode, performs image formation operation on thebasis of said data for printing to which no control command is appended,and performs image formation operation on the basis of, among the datafor printing which is stored in said storage unit, that data forprinting with the control command which has the same identificationinformation as said data for printing to which no control command isappended; and the information processing device having a printer driverprogram installed therein, the printer driver causing the informationprocessing device to execute: display processing to display a displayscreen upon said display unit to receive selection input to selectivelyset reduction of electrical power consumption of said image formingdevice, and to receive setting input of authentication information whichspecifies a user of said image forming device; data creation processingto create, according to said selection input, either data for printingto which a control command is appended to command reduction ofelectrical power consumption, or data for printing to which no controlcommand is appended; and output processing to output said authenticationinformation which has been inputted and set, along with said data forprinting to which a control command is appended or said data forprinting to which no control command is appended.
 19. An image formingsystem, in which an image forming device performing image formingoperation on recording paper according to printing data inputted withidentification information on a user, and at least one informationprocessing device having a display unit, are connected together so as tobe capable of mutual communication, the image forming device comprising:a control unit which controls image forming operation so as selectivelyto execute either an operating mode in which the state of electricalpower consumption is such that image forming operation can be executed,or a power save mode in which the state of electrical power consumptionis lower than during image forming operation; and a storage unit whichstores data for printing which has been inputted while said power savemode is being executed, and to which a control command which commandsreduction of electrical power consumption is appended, along with saididentification information; wherein said control unit, when data forprinting to which no control command is appended is inputted while saidpower save mode is being executed, changes over from said power savemode to said operating mode, performs image formation operation on thebasis of said data for printing to which no control command is appended,and performs image formation operation on the basis of, among the datafor printing which is stored in said storage unit, that data forprinting with the control command which has the same identificationinformation as said data for printing to which no control command isappended; and the information processing device having a printer driverprogram installed therein, the printer driver causing the informationprocessing device to execute: display processing to display a displayscreen upon said display unit to receive selection input to selectivelyset reduction of electrical power consumption of said image formingdevice; data creation processing to create, according to said selectioninput, either data for printing to which a control command is appendedto command reduction of electrical power consumption, or data forprinting to which no control command is appended; and output processingto output authentication information which specifies said informationprocessing device, along with said data for printing to which a controlcommand is appended or said data for printing to which no controlcommand is appended.